Heatricity: Turning Heat into Power

Now that summer has arrived in the northern hemisphere, there is plenty of it to go around. Computer hardware enthusiasts try to deal with it on a regular basis by incorporating gigantic fans, elaborate water-cooling systems, or even going that extra step toward phase cooling. Heat. It makes computer gamers and baseball pitchers go crazy alike - on days that exceed 32 degrees Celsius, there tends to be a higher frequency of batters being hit by pitchers. Fortunately, Orest Symko, a physicist at the University of Utah, and his team are developing ways to convert heat into sound and then into electricity. In the picture, he demonstrates by using a blowtorch to activate one of the devices he has been developing. Although you can't hear it, we assure you that a loud tone is being produced.

“Using sound to convert heat into electricity has two key steps. Symko and colleagues developed various new heat engines (technically called ‘thermoacoustic prime movers’) to accomplish the first step: convert heat into sound.”

“Then they convert the sound into electricity using existing technology: ‘piezoelectric’ devices that are squeezed in response to pressure, including sound waves, and change that pressure into electrical current. ‘Piezo’ means pressure or squeezing."

“Symko says the devices won't create noise pollution. First, as smaller devices are developed, they will convert heat to ultrasonic frequencies people cannot hear. Second, sound volume goes down as it is converted to electricity. Finally, ‘it's easy to contain the noise by putting a sound absorber around the device,’ he says.”

The heat engines are expected to have long lifetimes and require little maintenance since they lack moving parts. Symko expects the gadget to become an alternative to photovoltaic cells, which convert sunlight into electricity, within two years. There are plans to further test these heat engines at a military facility and at nuclear power plants. For many of us, this development may come as music to the ears.